Work cylinder



March 2, 1943. M. w. HUBER woRK CYLINDER Filed Sept. 17, 1941 muy? f ml Gttornegs Patented Mar. Z, 1943 WORK CYLINDER Matthew W. Huber, Chicago, Ill., assig'noi to Hydraulic Controls, Inc., a corporation of Illinois Application September 17, 1941, `Serial No. 411,236- 4 Claims. (C1. 121-38) ate clutches, machine brakes and like devices,y

and to operate various mechanisms on air craft. In the latter field, small size and light Weight and the ability to use small liquid conducting tubes for the motive fluid are important considerations.

, In these fields, simplicity, compactness and ease of disassembly are of more than ordinary importance.

The invention affords a simple compact arrangement of the return spring applicable to existing types of work cylinder using a selfaligning thrust rod.

Such an embodiment of the invention will now be described by reference to the accompanying drawing.

In the drawing:

Fig. 1 is a side elevation.

Flg. 2 is an axial section on the line 2-2 of Fig. 1.

The cylinder 5 is cast in one piece with a base plate having attaching lugs 6 provided with bolt holes as indicated. Formed on the cylinder 5 are diametrically opposed lugs or trunnions 1 which have enlarged heads as shown.

The piston comprises a cup-shaped skirt portion 8 and a head 9. The head 8 has a pilot II which is telescopically received in a guide recess formed in the skirt portion 8. Suilicient clearance'is aiorded at the end of Apilot II to permit proper compressive action on a gasket I2 which surrounds pilot II.

The gasket I2 is composed of rubber-like material, preferably one of the tough synthetic plastics having good resistance to the destructive effects of oils. A vent I3 is provided from the space to the right of pilot II. A coil compression follow-up spring Il, mounted in a cavity in head 9. develops the initial sealing pressure on gasket I2. Hydraulic pressure developed in head S increases the sealing pressure in proportion to the load.

The piston and seal construction are the invention of another and are not here claimed.

The push rod I5 has a rounded inner end -which engages the conical seat I6 within the cupped portion of the piston skirt l. It is provided with a vent Il serving as a continuation of the vent I3. The upper end of the push rod I5 is threaded as indicated at I8 to receive a clevis or other means for connecting the push rod to the work. It -will be observed that the rounded thrust end on the push rod permits limited angular displacement oi the push rod and this is availed of at times when the upper end of the push rod is connected to a lever or a swinging arm. The push rod is cross-drilled to receive a pin I9 which makes a rather loose fit and which is held against escape by the flange 2l formed on the periphery of the annular spring seat 22. The spring seat 22 sustains the inner end of a coil compression spring 23 which encircles the push rod I5 and bears at its outer end against a U-shaped spring seat member 24 which is provided with an aperture 25 in which the push rod I5 is guided and through which the push rod extends. The spring seat member M comprises a strap of wrough metal, preferably steel, which is provided near the end of each 'of its two arms with a circular aperture 26 each larger than the heads on the trunnions 1. This permits spring seat 24 to be sprung apart to clear the trunnions and then to be pushedinward compressing the spring 23 until the openings 25 pass over the heads of trunnions 1.4

The spring seat 24 is thus a substantially U- shaped stirrup which can be readily attached to and disengaged from the trunnions 1.

Attached to the outer end of the skirt portion 8 is an annular gasket 21 winch is conveniently of rubberized fabric and which is held in place by a retaining ring 28 attached by screws 29 to the end of the skirt portion 8. 'I'his gasket 21 produces a dus't excluding seal with the end of l the cylinder 5 when the piston is in its inner or inactive position. It also exercises a slight centering action on the push rod I5 and protects the space within the piston skirt 8 Aagainst the entrance o! dust and water.

vIt will be observed that even with the clevis or other connecting means mounted on the threads I8, the spring seat 24 may be disengaged from the trunnions 1 after which withdrawal of the pin I9 permits complete dismounting of all the spring and spring seat parts. No tools are required for this dismounting, a fact which is of considerable importance where the motor must be installed in a restricted space.

While the invention has been described in considerable detail, the description isintended to be illustrative rather than limiting. and modiications within the scope oi the claims are possible said spring; and interengaging means rendered effective by the action of the spring to prevent the escape of the arms from the lugs.

2. The combination of a cylinder having diametrically opposed trunnions; a piston working in said cylinder and having a socket to Areceive a push rod; a push rod having one end seated in said socket, the rod and socket being formed to permit limited lateral swinging o! the push rod; a spring seat on the push rod; a coil spring encircling said rod and at one end engaging said seat; and a generally U-shaped spring seat having an opening through which said push rod passes and around which the other end of said spring seats, said U-shaped spring seat having laterally displaceable arms with openings near the endg thereof, whereby such spring seat may be engaged with said trunnions.

3. The combination of a cylinder having diametrically opposed trunnions; a piston working in said cylinder and having a socket to receive a push rod; a push rod having one end seated on said socket; a spring seat releasably connected with said push rod and when released removable` therefrom by withdrawal over said seated end; a spring encircling said rod and at one end engaging said seat: and a generally U-shaped spring seat having an opening through which said push rocl` passes and around which the other end of said spring seats, said U-shaped spring seat having laterally displaceable arms with openings near the ends thereof whereby such spring seat may be engaged with said trunnions.

4. The combination oi' a cylinder closed at one end and open at the other, said cylinder having at its sides diametrically opposed trunnions: a piston working in said cylinder and insertable through the open end of the cylinder, said piston having on its side toward the open end oi the cylinder a socket to receive a push rod; a push rod seated in said socket and capable of limited angular motion :therein relatively to the piston; a spring seat releasably mounted on the push rod` and removable over the seated end thereof; a coll spring encircling said push rod and at one end engaging said Spring seat; and a second spring seat of generally U-shaped form having an opening through which said push rod passes and around which the other end of said spring seats, said U-shaped spring seat being formed oi iiexible metal with trunnion receiving apertures whereby' the spring seat may be ilexed to permit engagement of the trunnions in said openings, the engagement with the trunnions and the exibility of the spring seat being such as to accommodate limited angular motion of the push rod relatively to the cylinder and piston.

MATTHEW W'. HUBER. 

